We　examined　the　wake-up　effect　in　a　TiN/Hf0.4Zr0.6O2/TiN　structure.　The　increased　polarization　was　affected　by　the　cumulative　duration　of　a　switched　electric　field　and　the　single　application　time　of　the　field　during　each　switching　cycle.　The　space-charge-limited　current　was　stable,　indicating　that　the　trap　density　did　not　change　during　the　wake-up.　The　effective　charge　density　in　the　space-charge　region　was　extracted　from　capacitance-voltage　curves,　which　demonstrated　an　increase　in　free　charges　at　the　interface.　Based　on　changing　characteristics　in　these　properties,　the　wake-up　effect　can　be　attributed　to　the　redistribution　of　oxygen　vacancies　under　the　electric　field.